Fluid processing and transfer using inter-connected multi-chamber device

ABSTRACT

A micro-fluidic device comprises a body. The body defines pneumatic ports, chambers for receiving liquids, and a connecting conduit. Each port is sealed with a seal and is shaped to couple to a pneumatic conduit through the seal. At least some of the chambers each have a top opening and a bottom opening. The top openings are in fluid communication with corresponding ports. The bottom openings are in fluid communication with one another through the connecting conduit, which is above the bottom openings. Selective application of pneumatic pressures to the chambers through the pneumatic conduits can transfer a liquid from one chamber to another through the connecting conduit, for example, for processing bio-samples within the device.

CROSS-REFERENCE TO RELATED APPLICATION

This is the National Stage of International Application No.PCT/SG2008/000222, filed Jun. 23, 2008, which claims the benefits ofU.S. provisional application No. 61/064,871, filed Mar. 31, 2008, thecontents of which are incorporated herein by reference.

FIELD OF THE INVENTION

The present invention relates to fluid processing, more particularly tofluid processing and transfer using inter-connected multi-chamberdevices.

BACKGROUND OF THE INVENTION

Preparation of biological samples, such as DNA, RNA, mRNA and proteinfrom clinical samples in the forms of solids and fluids, may involve aseries of processing steps, such as tissue dissociation, cellseparation, cell lysis, gene extraction, and/or washing. This sometimesrequires complex fluidic delivery and processing protocols. In someconventional processing methods, samples and reagents are contained andmanually transferred using test tubes and micropipettes. This istime-consuming, labor-intensive, and prone to human error. There is alsoa significant risk of cross-contamination of nucleic acids betweendifferent samples. Some of the manual steps and operations may beautomated using robotic systems, but the robotic systems are difficultto use for handling small amounts of samples. Moreover, automationtypically requires added costs and expensive equipments.

A chip-based or cartridge-based micro-system can process a small amountof sample fluid within a closed fluidic system, thereby reducing risksof cross-contamination. Typically, the fluid flow within the chip- orcartridge-based systems is driven and regulated using pumps and valves.These systems have complex structures and low reliability, and areexpensive and inconvenient to use.

SUMMARY OF THE INVENTION

According to an aspect of the present invention, there is provided amicro-fluidic device comprising a body. The body defines first, secondand third pneumatic ports; first, second and third chambers; and aconnecting conduit. Each of the ports is sealed with a seal and shapedto couple to a pneumatic conduit through said seal. Each of the chambersis for receiving a liquid, and has a top opening and a bottom opening.The top opening of each chamber is in fluid communication with arespective port. The connecting conduit is above each one of the bottomopenings. The bottom openings are in fluid communication with oneanother through the connecting conduit. Selective application ofpneumatic pressures to the chambers through said pneumatic conduits cantransfer a liquid from one of said chambers to another one of saidchambers through said connecting conduit. Each one of said chambers mayhave a bottom surface sloped downwardly towards said bottom opening ofsaid each chamber. At least a section of said connecting conduit may beat a level above a liquid level in said chambers. The body may include atop portion, a bottom portion, and a middle portion. The chambers andconnecting conduit may be defined by said middle and top portions. Atleast a section of said connecting conduit may be adjacent said topportion. The top openings of said chambers may be adjacent said topportion. The ports may be defined by said bottom portion. The middleportion may define conduits each extending between one of the ports andits corresponding top opening. The middle portion may define conduitseach extending between one of the bottom openings and the connectingconduit. The top, middle and bottom portions may be separate portions,and the middle portion may be sandwiched between said top and bottomportions. At least one of said top and bottom portions may be formed ofa flat sheet. At least one of said top portion and said bottom portionmay be made of a plastic material. The body may define more than threeinter-connected chambers, such as six to eleven inter-connectedchambers. The liquid in a chamber may comprise a reagent, a buffer, asample, or a gene binding conditioner. At least two chambers may containdifferent liquids. At least a portion of said body may be made of apolymer. The polymer may comprise polycarbonate or poly(methylmethacrylate). The seal may be made of a plastic material. The body maydefine a gene extractor chamber. The gene extractor chamber may containa gene extractor and may be in fluid communication with said connectingconduit. The body may define a product chamber and a waste chamber, eachin fluid communication with said gene extractor chamber. The device maybe a cartridge. The pneumatic conduit may comprise a needle.

In accordance with another aspect of the present invention, there isprovided an apparatus comprising a device as described in the precedingparagraph, and a station connectable to said device for selectivelyapplying pneumatic pressures to said chambers through said ports of saiddevice. The station may comprise a base configured for coupling withsaid device, a plurality of pneumatic conduits mounted on said base,shaped to couple to said ports through said seals when said device iscoupled to said base, and a plurality of valves each connected to one ofsaid pneumatic conduits for selectively regulating a fluid flow throughsaid pneumatic conduits. A first set of the valves may be connected to afirst pressure device for selectively applying to said ports a firstpneumatic pressure, and a second set of the valves may be connected to asecond pressure device selectively applying to said ports a secondpneumatic pressure lower than said first pneumatic pressure. The firstpneumatic pressure may be higher than one atmosphere, and the secondpneumatic pressure may be lower than one atmosphere. The first pressuredevice may comprise a pressure pump, and said second pressure device maycomprise a vacuum pump. The station may comprise a controller forcontrolling operation of said valves and said pressure devices. Thestation may comprise a computer in communication with said controllerfor controlling operation of said controller.

In accordance with a further aspect of the present invention, there isprovided a method of operating the device described in the two precedingparagraphs, wherein at least one of the chambers contains a liquid. Themethod comprises coupling said pneumatic conduits to said ports;selectively applying different pneumatic pressures to said chambersthrough said ports, to cause said liquid to flow from one of saidchambers to another one of said chambers. The pneumatic pressures may beselectively applied to transfer said liquid sequentially through morethan two of said chambers.

Other aspects and features of the present invention will become apparentto those of ordinary skill in the art upon review of the followingdescription of specific embodiments of the invention in conjunction withthe accompanying figures.

BRIEF DESCRIPTION OF THE DRAWINGS

In the figures, which illustrate, by way of example only, embodiments ofthe present invention,

FIG. 1 is a block diagram of a fluidic apparatus, exemplary of anembodiment of the present invention;

FIG. 2 is a top plan view of a receptacle base for use in the apparatusof FIG. 1;

FIG. 3 is a cross-sectional elevation view of the base of FIG. 2 alongthe line A-A;

FIG. 4 is a bottom, see-through perspective view of a cartridge for usein the apparatus of FIG. 1, exemplary of an embodiment of the presentinvention;

FIG. 5 is a top exploded perspective view of the cartridge of FIG. 4;

FIG. 6 is a bottom plan view of the cartridge of FIG. 4;

FIG. 7 is a top perspective view of the top portion of the cartridge ofFIG. 4;

FIG. 8 is a bottom perspective view of the bottom portion of thecartridge of FIG. 4;

FIG. 9 is a top plan view of the middle portion of the cartridge of FIG.4;

FIG. 10 is a bottom plan view of the middle portion of the cartridge ofFIG. 4;

FIG. 11 is a cross-sectional elevation view of the base of FIG. 3coupled to the cartridge of FIG. 4 in operation;

FIG. 12 is a schematic diagram of a part of the cartridge of FIG. 4illustrating its operation, exemplary of an embodiment of the presentinvention;

FIGS. 13, 14 and 15 are schematic diagrams of a part of the cartridge ofFIG. 4 illustrating its operation, exemplary of an embodiment of thepresent invention;

FIG. 16 is an exploded perspective view of an alternative cartridge,exemplary of an embodiment of the present invention;

FIG. 17 is a bottom perspective view of the middle portion of thecartridge of FIG. 16;

FIG. 18 is a schematic diagram of the alternative cartridge illustratingits operation, exemplary of an embodiment of the present invention; and

FIG. 19 is a perspective view of an alternative base suitable forcoupling with the alternative cartridge.

DETAILED DESCRIPTION

Exemplary embodiments of the present invention utilize pneumaticpressures to selectively transfer liquids between inter-connected fluidchambers in a micro-fluidic device. The chambers are connected topneumatic ports through which pneumatic pressures may be selectivelyapplied in individual chambers above the respective liquid level. Thechambers may be interconnected through a connecting conduit that is atleast partially positioned above the liquid levels in the chambers forpreventing unintended liquid transfer between the chambers.

FIG. 1 is a schematic block diagram showing a system 100 for processingfluidic biological samples, exemplary of an embodiment of the presentinvention.

System 100 includes station 102 which can be a desktop station. Station102 is connected to a computer 104 and can receive a cartridge 106, aswill be further detailed below.

Station 102 also includes an embedded controller 108, which communicateswith computer 104, such as through a USB connection. Computer 104 may bea specially designed computer or a general-purpose computer loaded withspecially designed program for control the operation of system 100.

Station 102 also includes a plurality of pumps 110A and 1108 (alsocollectively and individually referred to as pump 110), miniature valvearrays 112A and 112B (also collectively and individually referred to asvalve array or valve 112) and a valve array control board 114. One ofthe pumps, such as pump 110A, is a vacuum pump; another pump, such aspump 1108, is a pressure pump. The pumps may be miniature pumps, such assyringe pumps or peristaltic pumps. In some embodiments, the flow rateprovided by the pumps may be from about 0.01 to about 50 ml/min. Inother embodiments, the flow rate may be different. The valves may beminiature electromagnetic valves. The pumps may be air pumps. However,in different applications, different gas or fluid pumps may be used. Indifferent embodiments, a pump 110 may be replaced with another pneumaticsource, which may be an external vacuum or pressure source. In somecases, the atmosphere may provide a suitable pneumatic source.

Controller 108 is adapted and configured to control the operation ofpumps 110 and valve arrays 112 through valve array control board 114.Controller 108 may include a microcontroller unit such as a PIC(“Programmable Intelligent Computer) microcontroller, or a programmablelogic controller such as an Omron programmable logic controller, or thelike.

Valves 112 are connected to a pneumatic interface 116. Valves 112 mayinclude miniature valves available from SMC™, or pinch valves availablefrom Cole-Parmer™, or other commercially available or specially designedvalves.

Interface 116 may include a receptacle/coupling unit or base 300illustrated in FIGS. 2 and 3. Base 300 includes a base portion 302 and awall portion 304 shaped for coupling with cartridge 106. A number ofpneumatic conduits, in this case needles 306, extend upwardly from andthrough base portion 302. Each needle 306 has an internal conduit and isconnected to a different valve in the valve array 112 for transferring afluid through the valve 112 and the needle 306.

An exemplary cartridge 106 is shown in FIGS. 4 to 10, exemplary of anembodiment of the present invention.

As shown in FIGS. 4, 5 and 6, the cartridge body 400 is formed of threeportions, a top portion 402, a middle portion 404, and a bottom portion406. The three portions may be separate portions and the middle portion404 is sandwiched between top and bottom portions 402 and 406. The threeportions 402, 404, 406 may be affixed together in any suitable manner.For example, the portions may be bolted together using bolts and nuts(not shown) or glued together using an adhesive. In some embodiments, itmay be convenient to removably mount the top and bottom portions to themiddle portion. For example, as illustrated in FIGS. 4 to 10, bolt holes408 may be provided for securing the portions together.

As shown in FIG. 5, top portion 402 may be shaped as a flat plate withbolt holes 408. Alternatively, top portion 402 may be formed of a thinfilm or sheet such as a plastic tape which has an adhesive side. Forexample, the adhesive side of the tape may have a glue layer on itssurface.

As shown in FIGS. 6 and 8, bottom portion 406 may be generallyplate-shaped but provided with bolt holes 408, pneumatic ports 410sealed with breakable seals 411 (not shown but see FIG. 11), a well 412,and fluid conduits or channels 414 and 416. Seals 411 may be formed ofan adhesive tape. Pneumatic ports 410 may be sealed using the adhesivetape. Alternatively, bottom portion 406 may also be formed of a flatsheet such as a plastic sheet with an adhesive side that faces middleportion 404. Each port 410 is shaped to couple to a pneumatic conduit,such as needle 306, through seal 411.

FIGS. 9 and 10 are top and bottom views of the middle portion 404respectively. As shown, middle portion 404 defines a number of chambers418A, 418B, 418C, 418D, 418E, 418F, 418G, 418H, 418I, and 418J (alsocollectively and individually referred to as chamber 418A). Each chamber418 has a top opening 420 and a bottom opening 422 (for easy viewing,only 422A, 422B, 422G and 420J, and 422J are labeled in FIG. 9).

Each top opening 420 is connected with a pneumatic conduit or channel424, which extends initially laterally and then downwardly to arespective pneumatic port 410 in bottom portion 406, so that thecorresponding chamber 418 is in communication with the respective port410 (for easy viewing, only channels 424A and 424J are labeled in FIG. 9and FIG. 10).

Each bottom opening 422A to 422H is connected with a liquid conduit orchannel 426 (labeled as 426A to 426H respectively), which extendsinitially laterally and then upwardly towards a top connecting conduit428 that extends along the top surface of middle portion 404. Bottomopenings 422I and 422J are connected to well 412 through conduits orchannels 414 and 416 in the bottom portion 406. Well 412 is connectedwith a conduit or channel 430, which extends upwardly to connectingconduit 428.

Thus, chambers 418 are each in fluid communication with a respectiveport 410 through its top opening 420, and are in fluid communicationwith one another through their bottom openings 422 and connectingconduit 428.

When the three portions are affixed together such as with bolts and nutsor with an adhesive tape or thermo-diffusion bonding, the channels aretightly sealed and form closed fluid conduits for allowing fluidcommunication between the chambers and between the corresponding pairsof pneumatic ports and chambers. The contacting surfaces betweenportions 402 and 404, and between portions 404 and 406, may contain, orcoated with, a sealing material. Well 412 when covered by bottom surfaceof middle portion 404 forms another fluid chamber, which may serve, forexample, as a gene extraction chamber, as will be discussed furtherbelow. The chamber formed by well 412 is not connected directly to apneumatic port, as it is not necessary to do so, as can be understood bypersons skilled in the art.

As can be appreciated, cartridge body 400 initially defines a closedfluid network therein. Top and middle portions 402, 404 when affixedtogether define chambers 418 and top connecting conduit 428therebetween. Top openings of chambers 418 are in fluid communicationwith corresponding ports 410. Bottom openings 420 of chambers 418 are influid communication with one another through connecting conduit 428.

Top openings 420 and connecting conduit 428 may be positioned at thesame level, adjacent top portion 402, as illustrated in the figures. Indifferent embodiments, connecting conduit 428 may be positioned higheror lower than top openings 420 but it should be at a level above thehighest bottom opening 422 of the chambers 418 that are interconnectedthrough connecting conduit 428 to prevent unintended transfer or mixingof the liquids contained in the chambers 418 through the connectingconduit 428. As can be appreciated, the allowable highest liquid levelin the chambers 428 is dependent on the level of the highest section ofthe connecting conduit 428. Thus, a higher connecting conduit 428 (up tothe top of the chambers) may be advantageous as it can allow moreeffective utilization of the chamber volume.

A chamber 418 may have a generally elongated cylindrical shape and asloped bottom, and may extend vertically between top and bottom portions402 and 406 (as better illustrated in FIG. 11). However, in differentembodiments, chambers 418 may have a different cross-sectional shape andmay be longer or shorter.

Cartridge body 400 or its portions may be formed using any suitablematerial. For example, each portion may be formed from a polymericmaterial, such as polycarbonate, poly(methyl methacrylate) (PMMA), orthe like. Top portion 402 may be formed of a thin sealing material suchas a plastic sheet with or without an adhesive surface. Seals 411 may beformed of any suitable sealing material such as a plastic film that canbe conveniently broken with the needles 306. The plastic film may or maynot have an adhesive layer on its surface.

The body 400 may be formed using traditional machining techniques, suchas microinjection molding and computerized numerically controlled (CNC)machining, or using plastic injection molding, as can be understood bypersons skilled in the art.

The internal surfaces of the chambers and channels may be cleaned orsterilized when desired or needed. In some cases, the internal surfacesof the chambers and channels may be coated with another polymermaterial, such as Teflon to modify the surface properties.

The sizes or dimensions of the cartridge 400 and the internal chambers418, fluid conduits/channels, or openings may vary depending on theapplication. For biological applications, the sample amount is typicallysmall, thus the fluidic chambers and channels may have dimensions on theorder of micro-meters. When the dimensions are too large, it may bedifficult to use pneumatic pressures to transfer small amounts offluids. On the other hand, the dimensions should be large enough toallow sufficient transfer rate of the fluids under pneumatic pressures.In typical applications, the fluid channels and openings may havedimensions in the range of about 0.2 mm to about 1 mm. The chambersshould have sufficient volumes for performing the particular desiredprocess or treatment. Each chamber 418 or other fluid chambers may havea volume on the order of 1 micro liter to 100 milliliter.

The particular shapes of the openings, channels, conduits, and ports mayvery in different embodiments and depending on the application.

In use, one or more chambers 418 may be filled, such as beingpre-loaded, with a liquid. The liquid may be a sample, a buffer, or areagent liquid, or any other desired liquid. A chamber may also be usedto store a product such as purified target genes, or to store wastes.Different chambers 418 may be initially loaded with different fluids.

The fluids may be loaded before covering the top surface of middleportion 404 with top portion 402. After loading the fluids, top portion402 is attached and affixed to middle portion 404 to close and seal theexposed openings at the top of middle portion 404 and to prevent leakageor contamination during transportation or operation. In someembodiments, a fluid may be initially loaded into a chamber through aport 410 before the port 410 is sealed. However, in many applications,loading from the top with top portion 402 removed may be moreconvenient.

As illustrated in FIG. 11, when cartridge body 400 is coupled to base300, seals 411 at ports 410 may be selectively broken by needles 306which will pierce through the seals 411, thus establishing fluidcommunication between corresponding valves in valve array 112 andchambers 418, through ports 410, conduits 424 and top openings 420.

The valves in valve arrays 112A and 112B are each connected to acorresponding needle 306 and configured to selectively regulate a fluidflow through that needle 306. The pumps 110 are connected to the valvearrays 112A and 112B for selectively applying a positive or negativepressure to the ports 310 through values 112.

Computer 104 controls the operation of controller 108, which in turncontrols the operation of pumps 110 and valves 112 to selectively applypressured air (positive pressure) or vacuum (negative pressure) to ports410, through needles 306. Depending on whether a positive or a negativepressure is applied at a port 410, a fluid may be selectivelytransferred to or from the corresponding chamber 418. If no change isneeded for a particular chamber, the port for that chamber may remainclosed, such as by closing the corresponding valve.

For example, to perform gene extraction for PCR (polymerase chainreaction), cartridge 400 may be loaded with fluids as illustrated inFIG. 12, which schematically shows a similar cartridge with somemodifications from cartridge 400. One modification is that some chambersare omitted in FIG. 12 as they are not used for this particularoperation; further the bottom. Another modification is that bottomopenings 424I and 424J are connected to connecting chamber 428 throughgene extraction chamber 412, not directly. However, the operationprocedure for transferring liquids between chambers 418B to 418F can bethe same despite these changes. Assuming chambers 418B, 418C, 418D,418E, 418F are loaded with sample, lysis buffer, conditioner, washbuffer, and elute buffer respectively. A gene extractor is deposited inwell 412. The gene extractor may include a magnetic-based extractor,silica membrane, silica beads or another material that can attach togenes in a fluid with a high iron concentration. The genes may includeDNA (Deoxyribonucleic acid), RNA (Ribonucleic acid), or mRNA (MessengerRNA). The gene extractor may be selected based on the particular genesto be extracted. Chambers 418I and 418J can be used for storing theproduct, extracted genes, and the waste produced by the reactionsrespectively. DNA or RNA degradation reagent may also be preloaded inone or more chambers.

In some cases, adjustment of the gene binding condition may be required.The buffers loaded in the chambers may include buffers for gene binding(such as pure or 70% ethanol) based on the target gene bindingconditions.

In one embodiment, to perform sample lysing, the valves 112corresponding to conduits 424D, 424E, 424F are closed. The valve 112Bconnected to conduit 424B is open and a pressurized gas such as air issupplied thereto, thus creating a positive pressure inside chamber 418B.The valve 112A connected to conduit 424C is open and a vacuum pressureis applied thereto, thus creating a negative pressure above the liquidin chamber 418C. The pressure differential thus drives sample liquidfrom chamber 418B to chamber 418C. Gas bubbles may also be createdinside chamber 418C, facilitate mixing of the sample with the lysisbuffer, after the sample liquid is completely transferred to chamber418C. The sample may thus be mixed with the lysis buffer thoroughly tolyse the sample and to protect the genes from degradation.

A similar procedure may be used to transfer the lysed sample to chamber418D to mix with the binding conditioner, thus adjusting the sample'sgene condition.

The conditioned sample may be then transferred to well 412 directly orthrough one or more of chambers 418E and 418F, depending on theparticular application as will be understood by those skilled in theart.

When magnetic beads are used as the gene extractor for gene extraction,the lysed sample may be mixed with the magnetic beads in well 412 usinga similar procedure, without first going through the other chambers.

Gene extraction may also be performed in well 412 with the pre-treatedsample fluid transferred from another chamber such as chamber 424D. Thetarget genes in the sample will be attached to the gene extractor. Theremaining liquid may be transferred to chamber 418J as waste.

Gene purification may be performed by transferring the wash buffer fromchamber 424E to well 412. One wash buffer or different types of washbuffers may be used to wash the genes in multiple steps. If multiplewash buffers are used, two or more chambers may be allocated to storewash buffers. In one embodiment, wash buffer may be transferred fromchamber 418E to chamber 418J, through well 412 and conduit 414. Thewaste may be later discharged from chamber 418J if the cartridge is tobe recycled, or disposed with the cartridge.

Gene elution may be performed by transferring the elution buffer fromchamber 418F to chamber 418I through well 412 and conduit 416. Theelution buffer will release the genes attached to the gene extractor andcarries the genes to chamber 418F. The target genes collected in chamber418I may be withdrawn using pipette or syringe for downstreamapplications, such as gene amplification and detection. Extracted genesor other reaction products may be transferred to a detection chamber(not shown) for detection of certain signals or target. The detectionchamber may be provided within cartridge 116 or may be provided in anexternal device (not shown) which can receive the material fromcartridge 116.

The operation of selectively transfer a fluid between the chambers isfurther illustrated with a simplified schematic diagram of the cartridgeshown in FIGS. 13, 14 and 15. For simplicity, only three chambers areshown in these figures but it should be understood that more chambersmay be operated in a similar manner.

As shown in FIG. 13, in an exemplary application, each of chambers 418A,418B and 418C is filled with a liquid reagent 432A, 432B or 432Crespectively. Ports 410A, 410B and 410C are initially sealed.

As shown in FIG. 14, in order to mix reagents 432A and 432C in chamber418C, a positive gas (using air or another gas, such as an inert gasincluding N₂) pressure may be applied at port 410A and a vacuum pressuremay be applied at port 410C, while port 410B may remain closed such asby closing the corresponding valve 112. The pneumatic pressure willdrive reagent 432A through bottom opening 422A, connecting conduit 428and bottom opening 420C into chamber 418C. Thus, reagents 432A and 432Ccan be brought into contact or mixed in chamber 418C. Due to thepositive pressure within chamber 418B, reagent 432A is prevented fromflowing into chamber 418B. The reagent in chamber 418A can be completelytransferred to chamber 418C.

As shown in FIG. 15, reagent 432A may be completely transferred tochamber 418C, while reagent 432B remains in chamber 418B.

Because the connecting conduit 428 is above the liquid level in thechambers, and the pneumatic pressure is applied through the top opening,air can bubble through the liquids without driving the liquid out of thecartridge through the pneumatic ports. Conveniently, the air bubbles canbe used to mix the reagents in the chambers such as in chamber 418C asshown in FIG. 15.

Conveniently, fluid transfer, mixing and processing may be effectedwithout using any internal valves, pumps or other fluid regulatingdevices in the cartridge. The fluid transfer may be effected entirely byselectively applying pneumatic pressures to different ports. Thisprocess may be automated using computer 104 and controller 108. In someembodiments, the chambers may be interconnected such that a fluid may betransferred from any selected chamber to another selected chamber, ormay be transferred sequentially from one to another through a series ofchambers.

As can be understood, the exemplary cartridges described herein issimple in construction and can be made at relatively inexpensively.Since there is no moving parts in the cartridge it is very reliable.Since the sample and reagents can remain in a closed system duringtransportation and even during operation, the risk of contamination issignificantly reduced.

The cartridge can also be conveniently configured and adapted for use indifferent applications, with different materials. Embodiments of thepresent invention can also be conveniently integrated with other systemssuch as a gene amplification unit or a gene detection unit.

In another embodiment, cartridge 116 may have an alternativeconstruction, such as having a cartridge body 400′ illustrated in FIGS.16, 17 and 18. In cartridge body 400′, processing chambers and channelsare provided within middle portion 404′. Top and bottom portions 402′and 406′ may be formed of flat sheets with no fluid channel or cavities.The flat sheets may have an adhesive surface, and may be formed ofpolymer tapes. The conduits and channel features may be entirelyprovided within the middle portion. The pneumatic ports 410′ are alsoprovided within middle portion 404′ and are sealed by bottom portion406′. Thus, bottom portion 406′ serves as a seal in this embodiment.

Cartridge body 404′ may define three or more chambers, which are used toinitially receive a sample, a wash buffers and an elute buffer,respectively; a gene extractor chamber 412′; and two chambers forstoring extracted and purified genes and wastes respectively duringoperation, as illustrated in FIGS. 16, 17 and 18. The chamber may beformed of through holes in middle portion 404′.

As better shown in FIGS. 16 and 18, the chambers in the alternativecartridge 400′ may include a gene extractor chamber 412′ and a wastechamber 418′. The remaining chambers shown may be used as reagentchambers for receiving samples and other reagent fluids or the extractedgenes. A difference between the cartridges 400 and 400′ is that thechambers for storing the waste and the product genes in cartridge 400′do not have a bottom opening but their top openings are connected toboth the pneumatic ports and the extraction chamber 412′. As can beseen, a plurality of connecting conduits 428′ are directly connected tothe top opening of gene extractor chamber 412′ in a radial arrangement,which are respectively connected to the other corresponding chambers.The other chambers, which have top and bottom openings similar to thosedescribed above with regard to body 400, are arranged around chamber412′.

As illustrated, extractor chamber 412′ is located at the center ofmiddle portion 404′ in the sense that other fluid chambers, except thewaste chamber, are located around chamber 412′. A gene extractor 434,which may have a cup-shape, may be placed at the bottom of extractorchamber 412′.

During use, pre-loaded sample and washing buffers may be transferred,under pneumatic pressure, to gene extractor chamber 412′ throughchannels 428′. A pre-loaded elute buffer may also be transferred to geneextractor chamber 412′ to elute genes via channel 428′.

For coupling to cartridge body 400′, the receptacle base of thepneumatic interface 116 may be modified as shown in FIG. 19, so thatmodified base 300′ can be properly coupled to the alternative cartridge400′ and the needles 306′ are arranged to match the locations of thepneumatic ports 410′ on the cartridge 400′. Needles 306′ can thus passthrough bottom portion 406′ (acting as a seal) and communicate withpneumatic ports 410′ when cartridge 400′ is coupled to base 300′.

In use, the alternative cartridge 400′ may be operated in a similarmanner as described above with regard to cartridge body 400.

As can be understood, it is not necessary that the cartridge in anembodiment of the present invention to be provided with an internalintegrated detector, or a detection window. Instead, the cartridge maybe coupled to another unit that includes detectors and other detectiondevices. For this purpose, the body of the cartridge may be made of amaterial that is suitable for use with the particular detection methodto be used. For example, the body may be made of a transparent materialwhen an optical detection method is to be used, or a non-magneticmaterial when a magnetic probe is to be used.

As described above and shown in the figures, it is not necessary thatevery chamber in the cartridge is connected to a pneumatic port. The topand bottom openings of a chamber may be respectively connected todifferent connection channels or conduits.

Also as shown in FIGS. 11, 12 to 15, and 18, the bottom of a chamber mayhave a bottom surface that is sloped downwardly towards the bottomopening of the chamber. The bottom surface may be generally cone-shaped.Such a sloped bottom surface may be advantageous as the fluid in thechamber can be conveniently withdrawn through the bottom opening due tothe gravitational force. In other words, the dead volume in the chamberis reduced or minimized with such a sloped bottom. While the bottomopening is shown to be located at the centre of the chamber in thefigures, this is not necessary. The bottom opening may be relocated offcentre. As long as the bottom opening is at the lowest level in thechamber and the bottom surface is sloped downwardly towards it, the samebenefit may be obtained.

Of course, modification to the system and cartridge described herein ispossible. For example, the cartridge body may have differentconstructions depending on the particular application. The shapes andnumber of chambers may vary. Each chamber may have more than one top orbottom openings. The top or bottom openings may be moved to the sidewall of the chamber as long as they remain separated by a sufficientvertical distance to allow a sufficient amount of liquid to be receivedwithout losing liquid, or allow all liquid in the chamber be withdrawnthrough the bottom opening by applying pneumatic pressure.

As now can be understood, it is not necessary that the body of cartridge106 is formed of three separate portions or layers. The cartridge may beformed from a single block of materials. However, layered constructionmay be convenient for manufacture and pre-loading of the fluids.

It is not necessary that the pneumatic ports 410 are located at thebottom portion of the cartridge body 400. The ports may be positionedelsewhere such as at the top or on the size of the body 400.

The top portion 402, the seals 411, or the bottom portion 406, may beremovable and replaceable so that the cartridge 106 may be convenientlyre-used.

Multiple connecting conduits 428 may be provided between differentchambers. To isolate the liquids in different chambers, it my besufficient that at least a portion of each connecting conduit 428 is ata level above the highest liquid level in the chambers 418 that areinterconnected through that connecting conduit 428.

It is not necessary that the pump is provided within station 102. Forexample, when available, any compressed air supply or source may be usedto apply positive air pressure to the ports. Any available vacuum sourcemay also be used.

In the embodiments shown in the drawings, the cartridge 106 may includesix to eleven fluid chambers. In different embodiments, the number ofchambers may be different depending on the particular application.Further, it is not necessary that all the chambers are at the same levelor that all chambers are inter-connected. For example, a chamber may bepositioned above or higher than another chamber. It should be understoodthat the term “above” as used herein do not require that one chamber isdirectly above another chamber. It is sufficient if the bottom level ofone chamber is at a higher level than the bottom level of the otherchamber. Further, it should be understood that the terms “higher” or“lower” is used with the assumption that the cartridge body is placed inan upright position with the top portion on top.

While needles 306 and seals 411 may be conveniently used in someembodiments, particularly when the size of the ports are small, thepneumatic conduits and the coupling between a pneumatic port 410 and apneumatic conduit for selectively applying a pneumatic pressure may beprovided in different manners. For example, other types of couplingarrangements may be used in different embodiments.

In different embodiments, a different base station that is connectableto the cartridge 106 may be used for selectively applying pneumaticpressures to the chambers 418 through ports 410. The base station mayinclude a base configured for coupling with the cartridge body 400,pneumatic conduits mounted on the base for coupling with ports 410 toselectively apply the pneumatic pressures through the seals 411. Thebase station may also include valves each connected to a pneumaticconduit for regulating the fluid flow therethrough. A controller may beprovided for control the operation of the valves. Each pneumatic conduitmay be connected to two valves, which are in turn connected to twodifferent pressure devices, one for applying a first pneumatic pressureand the other for applying a second pneumatic pressure lower than thefirst pneumatic pressure, so that the difference in the pneumaticpressures is sufficient to cause fluid transfer between the chambers inthe cartridge. The pressure devices may include pumps, a pressured gas(such as pressured air) line, or a vacuum line. The first pressure maybe higher than one atmosphere and the second pressure may be lower thanone atmosphere. In some embodiments, both pressures may be higher thanone atmosphere. The pumps may be separately provided or integrated withthe base station. The applied pressures and the valves may beautomatically or manually controlled.

As now can be understood, the methods and apparatus described herein canbe used to transfer and process raw biological materials that containgenes protein and reagents. After pre-treatment, the target genes orprotein can be extracted using the same apparatus. Different rawbiological materials can be processed using embodiments describedherein, which include blood, cultured cells, serum, other types of bodyfluids, and the like. The target genes can be DNA, RNA, mRNA, protein,or the like.

Exemplary embodiments described herein can be used in variousapplications, including as part of a clinical or point-of-care diseasediagnostics system, for sample preparation in research or clinical use,in forensic studies or sample processing, in the field of disease ormedical research, in the field of chemistry or biological research suchas molecular chemistry research, or in other similar fields.

Other features, benefits and advantages of the embodiments describedherein not expressly mentioned above can be understood from thisdescription and the drawings by those skilled in the art.

Of course, the above described embodiments are intended to beillustrative only and in no way limiting. The described embodiments aresusceptible to many modifications of form, arrangement of parts, detailsand order of operation. The invention, rather, is intended to encompassall such modification within its scope, as defined by the claims.

1. A micro-fluidic device, comprising: a body defining first, second andthird pneumatic ports, each sealed with a seal and shaped to couple to apneumatic conduit through said seal; a first chamber for receiving afirst liquid, having a first top opening and a first bottom opening,said first top opening in fluid communication with said first port; asecond chamber for receiving a second liquid, having a second topopening and a second bottom opening, said second top opening in fluidcommunication with said second port; a third chamber for receiving athird liquid, having a third top opening and a third bottom opening,said third top opening in fluid communication with said third port; anda connecting conduit above each one of said first, second and thirdbottom openings, said bottom openings in fluid communication with oneanother through said connecting conduit, wherein selective applicationof pneumatic pressures to said chambers through said pneumatic conduitstransfers a liquid from one of said chambers to another one of saidchambers through said connecting conduit.
 2. The micro-fluidic device ofclaim 1, wherein each one of said chambers has a bottom surface slopeddownwardly towards said bottom opening of said each chamber.
 3. Themicro-fluid device of claim 1, wherein at least a section of saidconnecting conduit is at a level above a liquid level in said chambers.4. The micro-fluidic device of claim 1, wherein said body comprises atop portion, a bottom portion, and a middle portion, said chambers andconnecting conduit defined by said middle and top portions.
 5. Themicro-fluidic device of claim 4, wherein at least a section of saidconnecting conduit is adjacent said top portion.
 6. The micro-fluidicdevice of claim 4, wherein said top openings of said chambers areadjacent said top portion.
 7. The micro-fluidic device of claim 4,wherein said ports are defined by said bottom portion.
 8. Themicro-fluidic device of claim 4, wherein said middle portion defines afirst conduit extending between said first port and said first topopening, a second conduit extending between said second port and saidsecond top opening, and a third conduit extending between said thirdport and said third top opening.
 9. The micro-fluidic device of claim 8,wherein said middle portion defines a fourth conduit extending betweensaid first bottom opening and said connecting conduit, a fifth conduitextending between said second bottom opening and said connectingconduit, and a sixth conduit extending between said third bottom openingand said connecting conduit.
 10. The micro-fluidic device of claim 4,wherein said top, middle and bottom portions are separate portions, saidmiddle portion being sandwiched between said top and bottom portions.11. The micro-fluidic device of claim 10, wherein at least one of saidtop and bottom portions is formed of a flat sheet.
 12. The micro-fluidicdevice of claim 4, wherein at least one of said top portion and saidbottom portion is made of a plastic material.
 13. The micro-fluidicdevice of claim 1, wherein said body defines more than threeinter-connected chambers.
 14. The micro-fluidic device of claim 13,wherein said body defines six to eleven inter-connected chambers. 15.The micro-fluidic device of claim 1, wherein said liquid comprises areagent, a buffer, a sample, or a gene binding conditioner.
 16. Themicro-fluidic device of claim 1, wherein at least two of said chamberscontain different liquids.
 17. The micro-fluidic device of claim 1,wherein at least a portion of said body is made of a polymer.
 18. Themicro-fluidic device of claim 17, wherein said polymer comprisespolycarbonate or poly(methyl methacrylate).
 19. The micro-fluidic deviceof claim 1, wherein said seal is made of a plastic material.
 20. Themicro-fluidic device of claim 1, wherein said body defines a geneextractor chamber, said gene extractor chamber containing a geneextractor and being in fluid communication with said connecting conduit.21. The micro-fluidic device of claim 20, wherein said body defines aproduct chamber and a waste chamber, each in fluid communication withsaid gene extractor chamber.
 22. The micro-fluidic device of claim 1,wherein said device is a cartridge.
 23. The micro-fluidic device ofclaim 1, wherein said pneumatic conduit comprises a needle.
 24. Anapparatus comprising a device as defined in claim 1, and a stationconnectable to said device for selectively applying pneumatic pressuresto said chambers through said ports of said device.
 25. The apparatus ofclaim 24, wherein said station comprises: a base configured for couplingwith said device, a plurality of pneumatic conduits mounted on saidbase, shaped to couple to said ports through said seals when said deviceis coupled to said base, and a plurality of valves each connected to oneof said pneumatic conduits for selectively regulating a fluid flowthrough said pneumatic conduits.
 26. The apparatus of claim 25, whereina first set of said plurality of valves are connected to a firstpressure device for selectively applying to said ports a first pneumaticpressure, and a second set of said plurality of valves are connected toa second pressure device selectively applying to said ports a secondpneumatic pressure lower than said first pneumatic pressure.
 27. Theapparatus of claim 26, wherein said first pneumatic pressure is higherthan one atmosphere, and said second pneumatic pressure is lower thanone atmosphere.
 28. The apparatus of claim 27, wherein said firstpressure device comprises a pressure pump, and said second pressuredevice comprises a vacuum pump.
 29. The apparatus of claim 26, whereinsaid station comprises a controller for controlling operation of saidvalves and said pressure devices.
 30. The apparatus of claim 29, whereinsaid station comprises a computer in communication with said controllerfor controlling operation of said controller.
 31. A method of operatingthe device of claim 1, wherein at least one of said chambers containssaid liquid, comprising: coupling said pneumatic conduits to said ports;selectively applying different pneumatic pressures to said chambersthrough said ports, to cause said liquid to flow from one of saidchambers to another one of said chambers.
 32. The method of claim 31,comprising selectively applying said pneumatic pressures to transfersaid liquid sequentially through more than two of said chambers.